Integrated circuits (ICs) may include sensors for a variety of reasons. For example, ICs may comprise moisture-sensitive sensors to detect liquid or humidity. Manufacturers may include a moisture-sensitive sensor to determine whether an IC has been damaged by immersion in water, so as to know whether a customer returning an IC is entitled to a replacement of the IC under warranty. Other ICs include sensors that are part of the functionality of the IC. For example, ICs have sensors to detect: radio frequency identification, temperature, ambient light, mechanical shock, liquid immersion, humidity, CO2, O2, pH, and ethylene. These IC chips may be used to monitor these ambient conditions.
Integrated circuit devices that operate as sensors may require a specific opening in the package to be able to act as an environmental sensing device. Conventional sensing devices use tape assist in the mold operation to create a cavity in the package. That technology is expensive and there are problems associated with it, in particular, damage to the sensor area (for example, die surface scratches, puncture marks in the sensor area or resin bleed from the molding operation). These problems continue to be the major issues with the tape assist art. Thus, a need exists for a plastic package for use as a housing for an integrated circuit device with an opening providing for a sensing area, wherein the sensing area must be free of resin bleed from the molding operation and must be free of damage.